Apparatus for projection of molten pulverized bodies



Aug. 2, 1938. p, c BENQIT 2,125,764

APPARATUS FOR PROJECTION OF MOLTEN PULVERIZED BODIES Filed Oct. 19 1955 Fig.1

Patented Aug. 2, 1938 v APPARATUS FOR PROJECTION F MOLTEN i PULVEBIZED BODIES i Francois Philippe Charles Benoit, Paris, France sppiiootionootobor 1a, 1935, Serial No. sms In France October 31, 1934 1 Claim. (oral-12.2

The invention, which is an improvement in or,

. modification of the apparatus for projecting molten pulverized bodies which forms the subject of Patent No. 1,998,217 as improved upon or modifled by the invention forming the subject of Patent 2,072,845,1s concernedwith the cooling of the nozzle of the burner, in order to. prevent it from reaching an excessive temperature after prolonged operation, and with means for effecting i this cooling.

The burner disclosed particularly in Patent 2,072,845 gives a flame of very high temperature.

As a result. the temperature of the burner itself may rise gradually to a value such that it is necessary to limit the duration of use of the burner in .order to avoid upsetting of the flame and autoignition oi. the combustible mixture. These drawbacks are obviated by the present invention,

burner itself or around the burner a particular cooling system which prevents the temperature of the said burner from rising excessively. This cooling may be obtained by bringing air or any other suitable fluid in flow into contact with the I burner nozzle so as to abstract excessive heat from the metal and dissipate it outwardly.

In order to leave no doubt regarding the invention, I have hereinaiter described below, but by way of example only, some forms of construction, with reference to the accompanying drawing, in which:

Fig. 1 is an axial section of a burner provided internally with passages for cooling air, and, it

desired, provided externally with flns which increase the surface cooled bythe surrounding air. Fig. 2 is a transverse section on the line 11-12 of Fig. 1.

Fig. 3 is a transverse section on the line of Fig.1.. a l

Fig. 4 is a front view of the burner tip. As in the specifications of the said prior patents, there is shown in these figures, at 64, axially of the. burner, thedelivery passage for the current of aircarrying in suspension the powdermto be Projected. The gaseous combustible mixture is delivered by passages 61, said mixture being led by way of the annular groove I to the passages I which open at '9 at the burner tip around the let of air laden with powder.

An additional passage I is connected to a source of supply of compressed air; this air, which serves for the projection of the powder after it is fused in the heating flame, serves in the flrst which consists essentially in establishing in the lines in Fig. 1.

place for cooling the burner, and, in particular With this object in view, the air which is delivered by way of I is distributed by an annular groove Ill among passages Ill leading to the conical surface between the spool I and. the cap I50. An annular groove lei, cut for ex- 5 ample in thebore oi the cap lil. distributes this airamong' passages I52 extending along generatrices of the conical exterior surface of the spool M'L- It will be seen that 1: thus obtain jets oi compressed air issulngin the form of a ring around the flame and serving to propel the powder.

This air is heated during its flow along the passages I49, thus cooling the spool I" in which these passages are formed. 1

Further, in flowing through the passages I52,

the air cools both the spool M1 and the cap lill .ment of these fins may be varied.

Byway of example Fig. 4-shows radially disposed fins having a profilerepresented in dotted .These fins may be formed in parallel planes so as to be adapted for example 9 to natural air currents or currents set up by ventilation, having a determined orientation. Also, the cap I" may be surrounded by an envelope so as'to provide around it a jacket chamber in which may be circulated a suitable fluid, 35 such as air, water, oil, etc., adapted to cool .by convection the exterior'sur'iace of the cap I".

It sufllces to connect the said chamber to a source of fresh fluid and to provide it with a conduit for withdrawal of the heated fluld.. The circulation 49 of the said fluid may be obtained by any suitable means; and tubes for the delivery and discharge of the fluid may be flxed at any suitable points of the chamber. The chamber may also be prohas in particular the advantage that it permits of obtaining, by means of a single screw joint lit, the absolute sealing of the passages for the 50 supply of combustible mixture from. the passages for air to be projected, without requiring packings of leather, flbre, asbestos, etc.

On the other hand, the spool I41 is very readily removable, thus permitting increase or reduction oi the caloriflc'power oi the heating i'lame, de-

' 0!, respectively the powder-laden air passing by way of the conduits and II and the passage III of the cock .1. It suilices toiormin the plug I. 01' this cock an additional e, parallel to the III, and corresponding to these parallel passages or to the conduits 25a and II. These arrangements, which are extremely simple, are not represented in the drawing.

It will be understood that, without departing from the principle oimy invention, there may be made modifications to the above described embodiment which do not alter its spirit and am! suitable materials may be utilized for the realization or the invention. Further, the forms represented may be varied subject to the condition of satisfying the conditions indicated and achieving theendinview. Itistobeunderstoodonthe other hand that the various devices provided may be applied either separately or in combination.

For example, the tom of the passages 88 and I or 01' the grooves ill may be varied, notably depending on the method employed to form the same or depending on the direction it is desired to give to their termination at the tip 01' the burner.

What I claim is:

A burner for use in proiecting molten material comprising at least one member having the following conduits and arrangement thereof, a central conduit for the discharge of an air stream holding in suspension particles of the material to be melted, a plurality of gas conduits tor the discharge of a gaseous combustible mixture disposed around said central conduit and terminating at the burner tip in an annular series oi outlet orifices surrounding the outlet orifice oi the central conduit, and a plurality of air conduits through which air may be passed to cool said member and said gaseous combustible mixture, said air conduits throughout a part of their length being located closer to the central conduit than are the gas conduits and then crossing said gas conduits and terminating at the burner tip in outlet orifices which form an annular series surrounding the annular series of outlet orifices oi the gas conduits. 

